package cc.fine.svc.security.utils;

import javax.servlet.http.HttpServletRequest;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * CREATE BY funnyZpC ON 2018/5/3
 **/
public class IPUtils {
    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     *
     * @return ip
     */
    public static String getRealIP(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if( ip.indexOf(",")!=-1 ){
                ip = ip.split(",")[0];
            }
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }


    public static String getIp(HttpServletRequest request) {
        List<String> ipHeadList = Stream.of("X-Forwarded-For", "Proxy-Client-IP", "WL-Proxy-Client-IP", "HTTP_CLIENT_IP", "X-Real-IP").collect(Collectors.toList());
        for (String ipHead : ipHeadList) {
            if (checkIP(request.getHeader(ipHead))) {
                return request.getHeader(ipHead).split(",")[0];
            }
        }
        return "0:0:0:0:0:0:0:1".equals(request.getRemoteAddr()) ? "127.0.0.1" : request.getRemoteAddr();

    }

    private static boolean checkIP(String ip) {
        return !(null == ip || 0 == ip.length() || "unknown".equalsIgnoreCase(ip));
    }
}